1. Field of the Invention
The present invention relates to conversational computer systems, and more particularly to conversational systems with automatic speech recognition, natural language understanding and dialog management for multi-client access.
2. Description of the Related Art State-of-the-art conversational systems such as those described in Lamel et al., xe2x80x9cThe LIMSI ARISE System for Train Travel Information,xe2x80x9d International Conference on Acoustics, Speech and Signal Processing, Phoenix, Arizona, March 1999 and Ward et al., xe2x80x9cTowards Speech Understanding Across Multiple Languages,xe2x80x9d International Conference on Spoken Language Processing, Sydney, Australia, December 1998, have focused on a single access method (limited to either a desktop or a telephone). As more and more information is available in electronic form, with the information interaction becoming increasingly complex, it is desirable to provide access to information using the most natural and efficient interfaces. In particular, it is desirable to provide efficient interfaces with several devices (such as desktops, telephones and personal digital assistants (PDAs)) that can potentially be used to access information and to design interfaces that are similar and intuitive across a wide range of access methods and input/output modalities. However, such systems pose a design challenge due to the complexity needed to realize such a design.
Therefore, a need exists for a system and method for a multi-client access to a dialog system. A further need exists for a multi-client access system which provides an efficient platform for natural speech interaction.
In accordance with the invention, a method, which may be implemented by a program storage device readable by machine, tangibly embodying a program of instructions executable by the machine, for accessing a dialog system employing a plurality of different clients, includes providing a first client device for accessing a conversational system and presenting a command to the conversational system by converting the command to a form understandable to the conversational system. The command is interpreted by employing a dialog manager and a multi-modal history to determine the intent of the command based on a context of the command (and possibly a type of device employed to present the command). A second client device is determined based on a predetermined device preference stored in the conversational system. An application is abstracted to perform the command, and the results of the performance of the command are sent to the second client device.
In other methods, which may be implemented by a program storage device, the first client device may the same as the second client device or the second client device may be a plurality of client devices. The first client device and the second client device may include at least one of a telephone, a computer, a personal digital assistant or equivalent devices. The command may be presented in natural speech, the steps of recognizing the speech and converting the speech to a formal language may be included. The steps of outputting the results of the performance of the command to the second client device by speech synthesis may also be included. The command may be presented graphically, and the step of responding to the command by one or both of a graphical result and synthesized speech may be included. The step of providing a component abstraction interface to interface with applications such that the conversational system is shielded from details of execution of the application may be included. The step of querying a user via the first client device for information about the device preference and/or clarification of command information may also be included. The mediator preferably employs information about the first client device and/or the second client device to determine the context of the command.
A system for accessing a dialog system employing a plurality of different clients, in accordance with the invention, includes a device handling and abstraction system adapted to provide input and output interfacing to a plurality of different client devices. The device handling and abstraction system receives commands from at least one client device and converts the commands to a form acceptable to a conversational system. The conversational system is coupled to the device handling and abstraction system for receiving converted commands. The conversational system is adapted to interpret the converted commands based on a context of the command (and possibly the device used to present the command) to determine an appropriate application responsive to the converted command. The conversational system includes a device preference to which results of executing the converted commands are sent. An application abstraction system is coupled to the conversational system and is adapted for determining which applications are appropriate for executing the converted command. The application abstraction system is further adapted to interface with a plurality of applications and to shield the conversational system from communications with the applications.
In alternate embodiments, the plurality of different client devices may include at least one of a telephone, a computer, a personal digital assistant, or equivalents. A command may be input to a first client and a result may also be received by the first client. The commands may include graphical commands and speech commands. The results of executing the converted commands may be conveyed to a client device as one of or both of synthesized speech and graphics. The device preference may include a plurality of client devices. The converted commands may include a formal language converted from natural speech. The conversational system may include a dialog manager and a multi-modal history to determine the intent of the converted commands based on a context of the commands. The conversational system preferably includes a mediator which employs information about at least one of the plurality of different client devices and a client device of the device preference to determine the context of the command.
These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.